A series of experiments will be conducted investigating the temporal correlates of the contrast in English between voiced and voiceless stops and fricatives (e.g. b, g, z vs. p, k, s). Emphasis this year will be on environments such as clusters and unstressed syllables where little investigation has been done in the past. Some experiments will measure acoustic intervals from spectrograms as well as air pressure and flow records during production. Others will involve subjects perceptual identification of synthetically produced words and sentences. A second line of research will be to extend similar investigation to Japanese.